This is just IMO, but Netflix has been putting out better cartoons than CN, Nickelodeon and Disney Channel these days. Dragon Prince and Hilda are better than most of the content the big 3 have been churning out lately. Why do you think that is?

Netflix has some clunkers, too--Disenchantment just looked awful.
CN suffered from one of the most famous cases of Network Decay ever.
Nick leaned too hard on its cash cows (Spongebob, Fairly Oddparents, & Dan Schneider).
Disney Channel leaned too hard on its sitcoms & forcing all of its actors into pop music contracts.

There's a growing generation of kids who don't watch television. They view the content through other platforms like Youtube. Netflix is easy for parents to push on their kids. Hand them the Ipad and they're quiet for an hour. There's pressure to retain viewership.

Netflix also has an edge where they can push out more content, faster. It's the difference of having to say a billion dollars cash flow versus a hundred billion. Essentially some of these television networks are having a hard time competing with streaming services simply because in order to survive they need to coexist with one another to promote shows on said platforms.

@CaptHayfever mentioned Network Decay and that's a channel previously secure in its content bending to meet popular demand in the hopes of getting more viewership. It's just a glowing example of the landscape that the streaming giants are carving out of the economy. You can't alienate your originally intended demographic.

You know...I like 'Hilda'. I truly do. But I think it would be a better show if it were on network TV. Presumably it'd have some hardassed cigar-chomper overseeing it, insisting on cuts for time. 'Hilda' has fat it could stand to lose, and that it would be better without.

There's no one reason. Apart from the fact that quality is subjective, one thing that probably helps is Netflix can give a LOT of creative freedom to their directors. They don't have advertisers breathing down their necks threatening to pull their ads (and thus a stream of revenue) if they dare to have something that they don't approve of.

Contrary to popular belief, soccer moms are NOT in fact the prime sanitizers of content, but advertisers are.

Creative freedom is a double-edged sword. George Lucas had complete creative freedom when he made the Star Wars prequels. Hell, he had complete creative freedom when he made 'A New Hope,' and his cut of 'A New Hope' was evidently an absolute sh*tshow. 'A New Hope' was literally saved in editing.

I believe in allowing a creator some freedom, but...I mean, an editor is a creator as well. Give editors some credit for parsing 'A New Hope', and for making the likes of 'Les Miserables' and 'Moby-Dick' classics. (Have you read the unabridged versions of 'Les Mis' or 'Moby-Dick'? I have. The unabridged 'Moby-Dick' is about seventy pages too long. Melville goes off onto these weird tangential irrelevances about sperm-whale biology. I don't give a tin shilling about whales---------I'm here to see Starbuck pleading with Ahab to give up his mad quest, and Ahab realising how far he's fallen. It's tragic. That's the tear-jerker. Save the whale trivia for your non-fiction whale book, fool.